Method of making a synthetic detergent in cake form



NmrHon or MAKING A SYNTHETIC DETER- GENT 1N CAKE FORM George Barsky, & C0,, Inc.,

.ware

New York, N.Y., assiguor to E. F. Drew New York, N.Y., a corporation of Dela- No Drawing. Substituted for'abandoned application Serial No. 321,746, November 20, 1952. This application August 15, 1956, Serial No. 604,066

4 Claims. (Cl. 260-458) Patented May 12, 1959 ice the basic for making a cake therefrom. Preferably the reaction product is formed in accordance with the method set forth in the aforesaid application for patent. In order to form a bar or cake therefrom, applicant has discovered that the'condensation products have steep solubility curves so that when a relatively small amount of water is added thereto and heated, some of the condensation product dissolves in the water forming a pasty mass which flows readily. If suflicient water is used and a relatively high temperature is applied, most of the condensation product may go into solution. Therefore, it is preferred to use an insufficient amount of water to give a clear solution. Then the mass is allowed to cool preferably rapidly in a suitable mold or form so that it solidifies, forming a dry coherent body'even though a substantial amount of wateris present therein.

It has been common practice for a great many years to form soap into cakes or bars as a convenience for a number of uses. However, in recent years synthetic detergents of considerably greater efficiency have been developed and it is highly desirable to replace the soap with 'such synthetic detergents in bar or cake form. However,

most of the synthetic detergents do not readily lend themselves to formation into cakes as some of them are crystalline in character and the particles do not readily bind together. If a binder is used, it must be water-soluble and, therefore, dissolves out readily when the cake is used and the latter tends to disintegrate. Such detergents as sulphonic compounds can be formed into cakes but when used, the water causes the formation of slime and thus makes it difiicult to handle and there are substantial losses of the detergent.

The present invention is intended and adapted to overcome the difficulties and disadvantages inherent in the prior art, it being among the objects of the present invention to provide a cake or bar of a suitable synthetic detergent which is coherent, does not tend to disintegrate,

does not form slime and is not affected by humidity in the atmosphere.

It is also among the objects of the present invention to provide a cake of synthetic detergent which is slightly soluble in warm water, which is long lasting and has adequate detergent properties.

It is further among the objects of the present invention to provide a cake of the character described in which there are incorporated substantial amounts of modifying 7 agents without loss of effectiveness.

It is still further among the objects of the present invention to provide a simple method of manufacture of such a cake at a low cost.

In practicing the present invention there is provided a water-soluble salt of hydroxyethyl sulphonic acid. This is mixed with a fatty acid or a mixture of fatty acids and preferably the higher saturated fatty acids. For example, one may use the fatty acids obtained by hydrolysis of coconut oil or may take certain fractions of such fatty acids. myristic, palmitic and stearic. Preferably saturated higher fatty acids having at least 12 carbon atoms are used and sometimes it may be advisable to avoid the presence of any substantial amount of the unsaturated fatty acids; in such case, the fatty acids have an iodine number of not over 2.0.

The hydroxyethyl sulphonic acid salt is reacted under suitable conditions with a higher fatty acid in order to form a reaction or condensation product. This product The fatty acids used include lauric,

is usually in granular or subdivided form and is used as The amount of water used may vary considerably and in general it has been found that up to about 10 to 15 parts by weight of water to parts of the detergentis suflicient in practically all cases. The temperatures used are substantially above room temperatures and are usually from 40 to 100 C. At the higher temperatures, less water may be used. Various addition agents, fillers, abrasives, coloring materials, perfumes or the like may be introduced into the composition prior to casting into molds.

In making the reaction product the relative proportions of the constituents are such that there is present for each mol. of the hydroxyethyl sulphonic acid salt an amount of the fatty acid which is less than 1 mol., say 0.95 mol., and more than 0.6 mol. The mixture is heated in a closed reaction kettle while maintaining an inert atmosphere by the use of a suitable gas such as nitrogen or carbon dioxide. The heating is conducted at a temperature of about 200 to 300 C. for a sufficient length of time to complete the reaction between the constituents. Usually from 1 to 4 hours is sufiicient. A pressure is maintained which is usually somewhat below atmospheric but in all cases above 250 mm. After the substantial completion of the reaction the pressure is reduced to below 100 mm. and preferably to as low a point as practical in ordinary production equipment, say from 10 to 20 mm. The heating is continued for a sufficient length of time at the high vacuum to volatilize and remove any unreacted fatty acid present in the reaction product. It is desirable that the product have a very low free fatty acid number, say not over 5.0 and often as low as 2.0.

Usually a considerable excess of the hydroxyethyl sulphonic acid salt is used and it may be desirable to remove such excess from the reaction product. This can be accomplished by dissolving the reaction product in water and recrystallizing the same by usual methods, whereby the ethanol-sulphonic acid salt remains in solution. By this procedure it is found that the final product is dry and granular, and is nonhygroscopic.

The following are specific examples of the operation of the present'invention:

. Example 1 The reaction product may be made as follows:

1 mol. of hydroxyethyl sulphonic acid sodium salt and 0.8 mol. of a mixture of fatty acids in which lauric acid is the major constituent, containing not over 30% of the adjacent fatty acids and derived from the fractional distillation of the fatty acids of coconut oil, are heated in an atmosphere of carbon dioxide to 220 C.260 C. and maintained at said temperature for 2 hours or more. The pressure is maintained at about 300 mm. absolute pressure or somewhat higher for the aforesaid period until the reaction is substantially complete. The pressure is then decreased as rapidly as possible to not over 20 mm. and maintained at said temperature so that the 3 total elapsed time is at least 4 hours, of which about 1.5 hours is at the lowest pressure.

The mass is cooled as rapidly as possible with continuous agitation. As the cooling proceeds the physical condition of the reaction mass changes from a viscous liquid to a viscous mass and then to a brittle mass which granulates readily and forms powder or beads. After the contents of the reaction vessel have reached a relatively low temperature, say below 120 C. the mass may be removed. To further pulverize the mass to a uniform size, it is cooled to room temperature. The free fatty acid number of the product is approximately 5.0. During the entire operation oxygen is excluded from the reaction vessel.

To purify the product by removing unreacted salts, the product is dissolved in water to form a saturated solution at least 90 to 95 C. Water is evaporated to give a supersaturated solution and it is then cooled to room temperature. The product precipitates out and is separated from the mother liquor. If desired, the product may be Washed with a limited amount of water. The crystallized product is substantially free from excess of hydroxyethyl sulphonic acid compound.

Example 2 The following constituents are used in order to produce a detergent which is eminently suitable for laundering fine and delicate fabrics:

Parts by weight Reaction product 100 Water The water is heated to a temperature of about 98 C. and the reaction product is gradually added thereto with constant stirring while maintaining the temperature, until a uniform consistency is obtained. Then the composition is poured into a suitable mold and cooled to form a cake.

Example 3 The following composition may be used as a toilet detergent:

Parts by weight Reaction product 100 Water 8 Na stearate 20 Example 4 A highly effective laundry detergent or one adapted for heavy cleaning has the following composition:

Parts by weight Reaction product 100 Water 4 Trisodium phosphate Rosin The reaction product mixed with water is agitated and heated to substantially the boiling point of water or slightly below said temperature. The phosphate and Parts by weight Reaction product 100 Water 12 Pumice 10 Oarboxymethyl cellulose 1 The water is heated to a temperature of 85 to 90 C. with agitation, after which the reaction product is incorporated therein with constant agitation and maintaining of the aforesaid temperature. When it is entirely incorporated, the pumice is similarly introduced and thereafter the carboxymethyl cellulose is introduced and uniformly distributed therethrough. Then the complete mixture is cast into molds and cooled.

Although the invention has been described setting forth a number of specific embodiments thereof, the invention is not limited thereto as the several limitations are intended to emphasize the breadth of the invention. Various changes in the details thereof may be made without departing from the principles herein set forth. For instance, the amount of water used may be increased if the detergent is to be used during dry seasons or in dry climates. If the detergent is to be used in humid regions, then less Water may be incorporated therein. Usually the amount of water is from 1% to 12%, based on the weight of the reaction product.

Various temperatures of operation may be utilized, it being necessary that it be high enough so as to dissolve sufficient of the reaction product to act as a binder. However, the temperature should not be too high so as to avoid possible decomposition of said product.

While in the specification it is set forth that the sodium salt of the hydroxyethyl sulphonic acid is used, other water-soluble salts of said acid are equally suitable, including all of the alkali metal salts. Various addition agents having suitable functions may be introduced into the composition, such as fillers, rosin, soap, alkali metal phos phates and polyphosphates, alkali metal carbonates, earboxymethyl cellulose, pumice, infusorial earth, lanolin, essential oils and other substances. In making such additions, the reaction product is the major constituent and usually consists of 80% or more of the total composition. The filling materials are usually less than 20%. In some cases foaming agents in small amount may be introduced into the composition. The reaction product may be formed with other fatty acids than those specifically named herein but the latter are at present consid ered to be the best for the purpose.

The molding may be obtained by the use of pressure to form the cakes or bars. Or the mass may be extruded to produce bars which may then be cut to size, and the cakes then pressed to the desired shape. These and other changes may be made in the details Within the scope of the invention as defined in the claims appended rosin are intimately mixed and added to the hot mixture and incorporated uniformly therein. The composition is then cast and cooled.

Example 5 hereto.

I claim:

1. A method of making a detergent cake which comprises adding to the reaction product of a hydroxyeth ylsulphonic acid salt with a higher fatty acid an amount of water insufiicient to dissolve said product at room temperatures, heating said mixture to form at least a paste, and cooling to room temperature.

2. A method of making a detergent cake which comprises adding to the reaction product of a hydroxyethyl sulphonic acid salt with a higher fatty acid made by heating a mixture of said hydroxyethylsulphonic acid and higher fatty acid to a temperature of about 200300 C. at a pressure below atmospheric for a sufficient length .of time to cause a reaction between said substances, an amount of Water insufiicient to dissolve said product at room temperature, heating said mixture to about 40 .to C. to form at least a paste, and cooling the same to room temperature.

3. A method of making a detergent cake which comprises adding to the reaction product of a hydroxyethylsulphonic acid salt with a higher fatty acid made by heating a mixture of said hydroxyethylsulphonic acid and higher fatty acid to a temperature of about 200-300 C. at a pressure below atmospheric for a sufficient length of time to cause a reaction between said substances, 1 to 12 parts by weight of water insufficient to dissolve said product at room temperature, heating said mixture to about 40 to 100 C. to form at least a paste and cooling to room temperature.

4. A method of making a detergent cake which comprises adding to the reaction product of a hydroxyethylsulphonic acid salt with a higher {fatty acid made by heating a mixture of said hydroxyethylsulphonic acid and higher fatty acid to a temperature of about 200300 C. at a pressure below atmospheric for a suflicient length 6 of time to cause a reaction between said substances, an amount of water insuflicient to dissolve said product at room temperature, heating said mixture to about to C. to form at least a paste, compressing said mixture to form a cake, and cooling to room temperature.

References Cited in the file of this patent UNITED STATES PATENTS Re. 23,823 Molteni et a1. May 4, 1954 1,906,484 Nusslein May 2, 1933 2,356,903 Wood Aug. 29, 1944 2,385,614 Dreger Sept. 25, 1945 FOREIGN PATENTS 573,470 Great Britain Nov. 22, 1945 

1. A METHOD OF MAKING A DETERGENT CAKE WHICH COMPRISES ADDING TO THE REACTION PRODUCT OF A HYDROXYETHYLSULPHONIC ACID SALT WITH A HIGHER FATTY ACID IN AMOUNT OF WATER INSUFFICIENT TO DISSOLVE SAID PRODUCT AT ROOM TEMPERATURES, HEATING SAID MIXTURE TO FORM AT LEAST A PASTE, AND COOLING TO ROOM TEMPERATURE. 